It is known that adenosine ranges broadly in a living body and exhibits various physiological actions on the central nervous system, the cardiac muscle, the kidney, the lung, the smooth muscle and the like via its receptor. Four subtypes of adenosine receptors, A1, A2A, A2B and A3 have heretofore been known. The respective subtype-selective receptor antagonists and agonists are expected to exhibit their pharmaceutical effects based on the physiological meanings of the subtype and on the biological distribution thereof. Among them, the A2A receptors are localized in the brain, especially in the corpus striatum thereof, and as one of its functions, the inhibition of neurotransmitter release is reported (European Journal of Pharmacology, Vol. 168, p. 285, 1989). Accordingly, antagonists to the adenosine A2A receptor may be expected as agents for preventing and/or treating diseases associated with adenosine A2A receptor, such as Parkinson's disease, Alzheimer's disease, progressive supranuclear palsy, AIDS encephalopathy, Transmissible spongiform encephalopathy, multiple sclerosis, amyotrophic lateral sclerosis, Huntington's chorea, multiple system atrophy, cerebral ischemia, attention deficit hyperactivity disorder, sleep disorder, ischemic cardiopathy, intermittent claudication, diabetes, anxiety disorders (e.g., panic attack and panic disorder, phobia, obsessive-compulsive disorder, posttraumatic stress disorder, acute stress disorder, generalized anxiety disorder, anxiety physical symptoms or substance-caused), mood disorders (e.g., depression, dysthymic disorder, mood-circulatory disorder), restless legs syndrome (RLS), drug dependence (e.g., alcohol dependence), eating disorder, epilepsy, migraine and chronic musculoskeletal system pain.
On the other hand, a large number of compounds having thiazole skeleton are known (for example, see U.S. Pat. Nos. 5,314,889 and 5,189,049; Japanese Patent Application No. 335680/2003, Japanese Published Unexamined Patent Application No. 53566/2002, Japanese Patent Application Nos. 209284/1999 and 087490/1998; WO93/21168, WO96/16650, WO97/03058, WO01/52847, WO01/53267, WO01/74811, WO02/053156, WO02/053161, WO02/094798, WO03/000257, WO03/062215, WO03/062233, WO03/072554, WO03/075923, WO2004/002481, WO2004/014884, WO2004/041813 and the like); and as thiazole derivatives having adenosine receptor antagonism, known are thiazole derivatives having adenosine A3 receptor antagonism (see WO99/21555 and Japanese Published Unexamined Patent Application No. 114779/2001), thiazole derivatives having adenosine A2B receptor antagonism and adenosine A3 receptor antagonism (see WO99/64418 and US Patent Application Publication No. 2004-0053982), and thiazole derivatives having adenosine A1 receptor antagonism and adenosine A2A receptor antagonism (see WO03/039451).
Further, thiazole derivatives having furyl group at the 4 position thereof are known (see U.S. Pat. No. 6,489,476; WO02/03978, WO01/47935, WO00/38666, WO00/14095; Chemistry of Heterocyclic Compounds, 2002, Vol. 38, p. 873; Khimiko-Farmatsevticheskii Zhurnal, 1974, Vol. 8, p. 25; Journal of Medicinal Chemistry, 1970, Vol. 13, p. 638; Khimiya Geterotsiklicheskikh Soedinenii, 1969, Vol. 3, p. 498; Journal of Organic Chemistry, 1962, Vol. 27, p. 1351).
(Wherein R represents phenylmethyl, 2-furyl, 4-fluorophenyl, 2-fluorophenyl, 2,4-dichlorophenyl, 4-nitrophenyl, 2-nitrophenyl, 4-bromophenyl, 3-bromophenyl, 2-bromophenyl, 2-chlorophenyl, 3-bromo-2-methoxyphenyl, 4-tert-butylphenyl, 3-methylphenyl, 4-methylphenyl, 4-methoxyphenyl, 2-methoxyphenyl or phenyl.)
Also, thiazole derivatives represented the above-described general formula (A) are registered as a chemical library in CAS REGISTRY Database (Registry Nos. 341929-13-3, 341929-11-1, 341929-09-7, 341929-07-5, 341929-05-3, 341929-04-2, 341929-02-0, 341929-00-8, 341928-98-1, 341928-96-9, 341928-94-7, 341928-92-5, 341928-90-3, 341928-88-9, 341928-86-7, 341928-84-5, 341928-82-3 and 341928-80-1).